Animation of Thai cave shows the obstacles facing rescuers trying to extract the 12 boys and their football coach

Despite overnight rain showers, Thai authorities said the downpours did not change water level in cave.

Sunday's near-four hour rescue bid, led by British divers, was described as a “masterpiece” and saw the children swimming through the deadly tunnel network which claimed the life of a Navy SEAL last week.

They were guided out by two scuba divers each wearing full face breathing masks but are now being kept away from their parents over potential risk of infection, officials said.

The lads were named in local media as Monhkhol Boonpiam, 13, Prachak Sutham, 14, Natthawut Thakhamsai, 14, and Phipat Phothi, 15.

Dr Sam Oliver, from Bangor University, told The Sun Online the boys may be suffering from the "perfect storm" of psychological stress, sleep disruption, nutritional restriction and dehydration.

He said: "Work by our lab and others has shown all these factors can impair the immune system, most likely by increasing immunosuppressive stress hormones, and this increases risk of infection and illness.

"In time the lack of sun exposure may also add to stresses by decreasing vitamin D status."

Neil Greenberg, a professor with Defence Mental Health at King’s College London, said there was a possibility the boys could develop PTSD, a generalised anxiety disorder, or what is known as "adjustment disorder".

They would require a lot of support from family and friends after being freed, but until then it was important no-one - including the boys' family members - pass on their anxieties about the situation.

He said: "At this stage the whole focus has to be 'keep strong'. What they'll probably be trying to do is mention 'here we are, we're a team, we're going to be OK'.

"We know that when people are captive, for any reason, that when they get out of it there is a bounce back effect, we call it the transitional effect, from when they're released, to getting back to normal."